Our investigation will be addressed to the following questions: (1) Are the differences in anatomy and physiology one sees among individuals, populations, and species due to protein sequence differences or are they due to differences in regulation? (2) Do allelic proteins with the same charge often differ by multiple substitutions? How well does electrophoresis detect differences in the amino acid sequences of proteins? BIBLIOGRAPHIC REFERENCES: Nolan, R.A., Brush, A.H., Arnheim, N., and Wilson, A.C. An Inconsistency between Protein Resemblances and Taxonomic Resemblances: Immunological Comparison of Diverse Proteins from Gallinaceous Birds. Condor 76:154-159 (1975). Prager, E.M., and Wilson, A.C. Slow Evolutionary Loss of the Potential for Interspecific Hybridization in Birds: A Manifestation of Slow Regulatory Evolution. Proc. Nat. Acad. Sci. USA 71:200-204 (1975).